Vat dye and process of making same.



UNITED STATES PATENT wmag r RENE noun, or MANNHEIM, GERIIANY, Assxenoa TO Barns-CHE Amman semi FABRIK, OF LUDWIGSHAFEN- BADEN.

No Drawing.

To all whom it may concern:

Be, it known that; I, Ram-313mm, a c tizen or" the Swiss Republic, residing at Manuhcim, Germany, have in ented new and uset'ul Improvements in Vat- D ves and Processes or Making Same, of which the following is a specification.

The specification of Letters Patent No.

94820-1 describes the production of a monosulfouic acid of indanthrene by treating indanthrene blue with mild sulfonatiug agents, preferabl in the presence of boric acid. I have found that. on treating this" indanthrene monosulfonic acid so as to split ml the sulfonic acid group,- the original indanthrene blue is not obtained again, but a vat coloring matter is produced which dyes vegetable fiber shades of blue which a re greener than those obtained from-the indanthrone blue originally taken for the produc' tion of the monosulfonic acid. I have fur ther found that, in order to produce the new coloring matter, it is not necessary, first to prepare and isolate the sulfoui'c acid, as the said now coloring matter can also be obtained by heating indanthreneblue with sulfuric acid containing a small proportion of water for instance with from 92 to' 95 per cent. sulfuric acid, say, at a temperature of about 120 C. The heating is preferably carried out in the presence of boric acid, and should in any case be so conducted that the final product contains no cons erable quantitv of indanthrenesulfonic acid-- The following are examples ofv how my invention can be carried into practical effeet, but the invention isnot. confined to these examples. The parts are by weight.

Example 1: Heat together, -for six hours, at a temperature of one hundred degrees centigradc, ten parts of indunthrene blue, four parts ofa'nhvdrous boric acid, and two hundred parts of ninety-five per cent. sulfuric acid. Then pour the. reaction liquid into water and filter oil and wash the colorin matter.

Example 2: Heat together, at one hundred. and twenty degrees ceutigradc, while continually stirring, one hundred parts of sulfuric acid (ninety-two, to ninety-four, per cent.)

' and five parts of indanthrene monosulfonic acid which has been obtained by treating indant-hrene blue with a mild sulfonatnig ON-TIIE-RHINE, GERMANY, CORPORATION OF VAT DYE AND PROCESS OF MAKING SAME.

agent in thepres'cnce of boric acid. \Vhen:it

is found, from a test portion, that the color ing matter is insoluble in boiling water (which is the case after about six hours), pour the solution into Waterand filter oil and wash the coloring matter. which separates out.

The new'coloriug matter, 'when dry. a blue powder which is insoluble in water. alcohol, and dilute acids and alkalics. It differs from indanthicne blue in being somewhat soluble in glacial aceticacid and in dichlor-bcnzene, the solutions being blue. It. is easily soluble in nitrobenzene and quinnlin, the solutions being greenish blue. ilhe new coloring matter yields a vat more reach ily than does indanthrene blue. and can also be dyed from a cold vatwhen making use of only small quantities of caustic soda- N ow what- I claim 1s:-- 1. The process of reducing vatcoloring matter by heating in anthrene monosulfonic acid with sulfuric acid containing a small pro'iortiou of water so as to split off the sol onic acid group.

2. The process of matter by heating indanthrene blue with sulfuric acid containing a small proportion of .a

water, the heating being carried out so that the final product contains-no considerable trace of indanthrene sulfonic arid.

roducing vat; coloring. I matter by hcatmg'in ant-hrcne monosulfonzc 4. The process of prhducing vat coloring;

matter by heating indanthrene blue with sub uric acid containing a small proportion of water and disc some boric acid. the heating being carried out so that. the final produ t contains no considerable trace-of indauthrone sulfonic acid.

5. The processof producing vat coloring matter by heating lndanthwne blue with from ninety-two to ninety-live per m-nt. sulfuric acid ata temperature of about one hundred and twenty degrees centigrade.

6. As a new article of manufacture the val; coloring matter which can be obtained by heating indanthrcne blue with sulfuric acid containing av small proportion of water, which new vat coloring matter is insoluble in water, in alcohol, and in dilute acids and lit) alkaiivw smumvlmf soluble in glacial acetic In testimony whereof I have Inn-cumin set :u-id am] in div]!lnr-iycuzvnu yielding blue my hand in the prvsenco of hvn subscr bing sulu'likm vnsily mlubie in nitrobvnzcne and \vitn'es es. f

in qniuulin the snlutions living greenish blue, I RENE BOIIX, 5 and is rupublc of dyeing vegetable fiber Witnesses: 1 i

Trnm mt. greener shades of blue than does ERNEST L. has. thy u 'igiuu! indanflu'cneD1110. \V. N. Qmnumx 

